Sept. 12, 2005 -- A cluster of obesity-related heath risk factors known as metabolic syndrome, which dramatically raises the risk of heart disease and diabetes, poses a growing threat to the health of Americans and requires more aggressive treatment.
New guidelines, released jointly today by the American Heart Association and the National Heart, Lung, and Blood Institute (NHLBI), broaden the criteria for diagnosing the condition in an effort to catch and treat more people at risk.
"People are becoming overweight or obese early in life and therefore are developing metabolic syndrome earlier, increasing their risk of cardiovascular disease," says Scott Grundy, MD, PhD, chairman of the panel that compiled the guidelines, in a news release.
What Is Metabolic Syndrome?
Metabolic syndrome consists of several interrelated risk factors that have been shown to more than double the risk of heart disease and raises the risk of type 2 diabetes by up to fivefold. It affects more than a quarter of American adults or over 50 million people.
The traditional risk factors for metabolic syndrome include:
- Abdominal obesity (waist measurement of more than 40 inches in men or 35 in women)
- Elevated blood fat (triglycerides greater than 150)
- Reduced "good" high-density lipoprotein cholesterol (HDL); less than 40 in men and less than 50 in women
- Elevated blood pressure greater than 130/85
- Elevated fasting glucose greater than 100 mg/dL (a sign of insulin resistance)
Researchers say anyone with three or more of these risk factors should be considered to have metabolic syndrome. Other conditions often associated with metabolic syndrome include physical inactivity, aging, hormonal imbalance, and a family history of the condition.
Of these risk factors, they say the dominant risk factors for the syndrome appear to be abdominal obesity and insulin resistance.
Broader Criteria Needed for Some
While these traditional risk factors still stand for most individuals, researchers say some people who are not obese by traditional measures, who are insulin-resistant, and have other risk factors may also have metabolic syndrome.
These groups may include:
- People who have two parents with diabetes or one parent with diabetes and a first- or second-degree relative with diabetes
- People with a family history of insulin resistance
- Individuals of Asian ethnicity, who are prone to insulin resistance
For these groups, the new guidelines call for a marginally increased waist measurement of 37-39 inches in men and 31-35 in women to be considered in the diagnosis of metabolic syndrome.
"If there are three other clinical criteria present, then the diagnosis of metabolic syndrome can be made without an increased waist circumference," says Grundy, who is director of the Center for Human Nutrition at the University of Texas Southwestern Medical Center in Dallas.
The guidelines also broaden the definition of elevated blood pressure and fasting glucose that doctors should consider in diagnosing metabolic syndrome.
"This statement should serve as an alert to physicians that it is vitally important to identify and treat the growing number of people with metabolic syndrome," says NHLBI Director Elizabeth G. Nabel, MD, in the release. "For individuals with this syndrome, lifestyle treatment -- weight control and increased physical activity -- is the primary therapy for lowering their risk factors and reducing the long-term risk for heart disease."